Thursday, 25 February 2016

These pages are examples of some of the more recent science around biosolids and its land application. All raise serious issues about this practice. All state that more study needs to be done. All, in the absence of clear evidence of safety, suggest that we act with precaution.

Each Journal entry is followed by some quotes which highlight the problematic issues:

"More than 30,000 tons of pharmaceutical drugs are used in Germany annually. After being used for therapeutic purposes or being disposed of improperly (in toilets), residues of these drugs end up in municipal sewage systems. Depending on the sewage treatment methods used, a greater or lesser portion of the pharmaceutical drug residues removed from sewage are deposited in sewage sludge. According to a German Advisory Council on the Environment (Sachverständigenrat für Umweltfragen, SRU) report on pharmaceutical drugs in the environment, although only a handful of pharmaceutical drugs accumulate in sewage sludge, it would be advisable to gradually phase out the use of sewage sludge as a fertilizer so as to avoid diffuse loads of potentially harmful substances in soil [SRU]."

"Another study concerning the soil breakdown and mineralization of steroid hormones that end up in fields as the result of sewage sludge fertilization (among other applications) found that oestrogen is a stable compound in the soil. The study’s lab experiments showed that oestrogen in soil is subject to vertical displacement and should thus be factored into risk assessments concerning groundwater as well as surface waterbodies that are affected by groundwater. Another subject of debate among scientists concerning sewage sludge application on land is the spread of pathogens that are resistant to antibiotics. There is evidence that in part owing to the elevated bacterial concentrations found in sewage treatment plants, antibiotic resistance can be exchanged between bacteria that are input with sewage from facilities such as hospitals [UBA]. This phenomenon could potentially give rise to new constellations of antibiotic resistance being transmitted to heretofore nonresistant bacteria. According to another study [EIBISCH], the continuous input of antibiotics into soil over a prolonged period can result in elevated concentrations of bacteria that promote the growth of antibiotic-resistant bacteria, resulting in the possibility of gene transfers of the resistance genes of such antibiotics. Expert reports issued by the German Advisory Council on the Environment (SRU) concerning pharmaceutical drugs in the environment indicate that the spread of antibiotic resistance in the environment resulting from resistant bacteria inputs poses a greater public health hazard than antibiotic inputs per se [SRU]."

"Sewage sludge fertilizer is a pollution sink for harmful sewage components from households, businesses and diffuse sources, concerning whose environmental relevance too little is known. Notwithstanding tighter controls and stricter limit values for certain sewage sludge pollutants, uncontrolled pollutants such as hydrocarbons inevitably find their way into the soil. Incorporation of certain pollutants into the food chain cannot always be avoided, despite the fact that, for example, plants normally do not absorb organic pollutants. Nonetheless, new breakdown products of pharmaceutical drugs are discovered in sewage sludge all the time, and they are incorporated into sewage sludge via human excretion carried by the wastewater that is treated by sewage treatment plants."

A very good piece of objective journalism from The Guardian a few years ago, clearly maps out the issues with land application of "biosolids" –

"Switzerland - which used to land-apply 40% of its sludge - has banned the practice because of fears from farmers that it was harming their soil. The Netherlands has banned agricultural use of sludge, and national farmers' associations in France, Germany, Sweden, Luxembourg and Finland are against it, partly because of concerns about organic contaminants such as PCBs and brominated flame retardants (linked to liver and neuro-developmental toxicity and hormone disruption), which some research has shown persist in sludge."

A new study (2012) from Scientists at the University of Aberdeen "studying sheep maintained on pastures fertilized with sewage sludge ... found a high incidence of abnormalities in the animals." As the article states, "It is our opinion that all spreading of sewage sludge, humanure and biosolids on agricultural land in the UK should be stopped until it is PROVED to be safe"

"Engineered nanomaterials (ENMs) are entering waste streams in increasing quantities as a result of their use in an increasing variety of consumer products employing nanotechnology.1 The majority of these ENMs have been shown to partition to the sludge within wastewater treatment plants (WWTP), and there is a risk of environmental harm in agroecosystems where biosolids are land-applied as fertilizer, which has yet to be fully evaluated. While regulations exist that limit the land application of biosolids that contain elevated concentrations of certain metals, these regulations do not specifically consider the incorporation of metal-containing nanomaterials."

"While the metal concentrations used in this study are high relative to near-term predicted soil ENM concentrations, we have clearly demonstrated that there is a distinct plant and

microorganism response as a result of exposure to biosolids containing ENMs compared to biosolids containing bulk/dissolved metal of the same composition. This result suggests that soil accumulation of ENMs could potentially affect critical ecosystem services, agricultural productivity, and ultimately human well-being."

"The field of nanotechnology is developing rapidly, and engineered nanomaterials (ENMs) are being incorporated into an increasing number of industrial and consumer products. The ENMs within these products are being released into the environment, which raises concerns about their possible impacts on human and ecosystem health."

"In summary, this study provides the first comprehensive insight into the toxicogenomic responses of M. truncatula grown in soils amended with aged biosolids containing a mixture of

ENMs (Ag, TiO2, and ZnO). Considering the results from the companion study,18 the gene expression patterns are consistent with the hypothesis that inhibition of nodulation by ENM

exposure was a result of plant toxicity rather than microbial toxicity, particularly because population densities of S. meliloti were similar in the bulk/dissolved and ENM treatments. We identified multiple genes involved in nodulation and inorganic nitrogen metabolism that were down regulated. In addition, genes involved in oxidative stress response were up-regulated. The companion study showed that Zn concentrations and uptake were higher in shoots from the ENM treatment than in the bulk/dissolved treatment while Ti and Ag concentrations were not significantly different.18 The present study showed that several genes involved in metal binding and Zn homeostasis were up-regulated. Taken together, these findings suggest that inhibition of growth and nodulation in M. truncatula exposed to ENM treatment is likely the result of enhanced bioavailability of Zn ions in the biosolids-amended soil containing aged ENMs resulting in phytotoxicity."

"This study indicates that some CECs are sufficiently persistent and mobile to be vertically transported into the soil column following biosolids applications to the land surface, even in semiarid regions"

"Eggen et al. (2011) reported uptake of pharmaceuticals by plants (carrots, wheat and barley cereals, meadow fescue, turnip rape seed) and negative effects on growth and development of carrots; however, the wheat samples from the Colorado study were not analyzed for pharmaceutical CECs. Holling et al. (2012) reported pharmaceutical and triclosan uptake by cabbage roots and aerials."

"Triclosan, a synthetic antimicrobial compound, was persistent in biosolids through the 180 days of sampling (Figure 3). Large concentrations in the first (top) soil interval dissipated little over time."

"Concentrations of 4-nonylphenol (sum of all isomers), a detergent or metabolite, were substantial in the Colorado biosolids (approximately 200 ppm) and persisted through at least 180 days post-application"

"however, the persistence of this CEC in biosolids and soil indicates the potential for long-term environmental effects."

"A plasticizer and flame retardant, TBEP, was detected in biosolids at relatively small concentrations compared to other CECs but was consistently detected in biosolids through 180 days post-application"

"The results of this study indicate that CECs in biosolids persisted in a real field-application environment. Between 180 and 468 days post-application, select CECs migrated deeper into the soil profile or were taken up by plant roots."

"This study demonstrates that agronomic applications of biosolids result in detectable concentrations of CECs in soil, and that CECs can persist in surficial biosolids and in soil-biosolid mixtures at detectable concentrations on time scales exceeding one year, particularly under the semiarid conditions present at this study site."

"Perfluoroalkyl substances (PFASs) have been used for over the past 60 years in an increasing variety of consumer and industrial products, such as fire-retardant foams, inks, paper, lubricants,
cosmetics, upholstery and so on. As a result of the large production and wide application, PFASs are broadly present in the environment. Within the PFAS group, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the most commonly used and found compounds (Hu et al., 2011). They have garnered intense scientific and regulatory interests due to their extraordinary persistence, bioaccumulation tendencies and potential toxicological effects. So far, PFOS and PFOA have been found in atmosphere (Li et al., 2011), soil (Yoo et al., 2010), surface water (Hu et al., 2011), sediment (Higgins et al., 2005), and biota (Müller et al., 2011). They were also present in the serum of wildlife and humans and could be biomagnified in terrestrial and aquatic food webs (Müller et al., 2011; Houde et al., 2011). Sewage sludge is an important sink of PFOS and PFOA (Higgins et al., 2005; Sun et al., 2011). The land application of treated sewage sludge (biosolids) is the option favored internationally for sludge management as it contributes to improve soil fertility and properties (Clarke and Smith, 2011). However, the use of biosolids as fertilizer in agriculture can cause contamination of PFASs in soils (Yoo et al., 2010; Washington et al., 2010; Sepulvado et al., 2011; Wen et al., 2014). Organisms are liable to take up organic contaminants and may accumulate high level of PFASs when they live in contaminated soil environment. A few studies have been conducted and revealed plant uptake of PFASs from soils (Yoo et al., 2011; Wen et al.,2014; Zhao et al., 2014)."

"Accumulation of organic contaminants implies a risk to not only earthworm populations but also many vertebrate species feeding on earthworms. So far information about the accumulation of PFASs by earthworms from soil is quite limited."

"land application of biosolids not only increases the OM contents, but also results in the accumulation of PFASs in soils."

"Earthworms may take up contaminants from soil and porewater, both through their skin (dermal) and by ingestion (oral). It is assumed that only contaminants that can be released from
soil/sediment are available to biological receptors.....The results verified that the soil PFOS and PFOA concentrations and soil OM content ([OM]) are two key factors controlling the bioavailability of PFOS and PFOA in soils."

"These suggested that soil concentration and OM content dominated the bioavailability of PFASs in soils. Soil pH and clay content appeared relatively unimportant for PFOS and PFOA bioavailability....The results of this study demonstrated that contamination of PFOS and PFOA in soils as a result of biosolids land application led to accumulation of PFOS and PFOA in earthworms with higher concentration of PFOS than that of PFOA."

"A paired agricultural watershed study was conducted in the Collins Creek and Cane Creek watersheds in Orange County, North Carolina, to better understand the transport of nutrients and bacteria from biosolids application fields to groundwater and surface water and to provide a scientific basis for evaluating the effectiveness of the current biosolids land-application regulations"

"data for field properties and water-quality constituents, including metals, major ions, and contaminants of emerging concern (household-, industrial-, and agricultural-use compounds, pharmaceutical compounds, hormones, and antibiotics) also were collected and used in the analyses."

"Compared to the background field, the biosolids land-application fields had elevated concentrations of copper, mercury, molybdenum, TKN, and TP. The background field had the highest median concentrations of cadmium, lead, selenium, and fecal coliform. Finally, the median concentrations of five constituents (arsenic, chromium, nickel, zinc, and E. coli.) overlapped between the application fields and the background field. The potential short-term effect of land application of biosolids to agricultural fields was evaluated using both the chemical concentration and dry mass of the biosolids samples in relation to that of the (pre-application) soil onto which it was applied. "

"Selected biosolids and soil samples were collected and analyzed for contaminants of emerging concern (household-, industrial-, and agricultural-use compounds, sterols, pharmaceuticals, hormones, and antibiotics) from biosolids land-application fields ... Pharmaceuticals were largely detected only in the application fields and biosolids."

"Compounds that were often detected in both the biosolids-application soils and the biosolids samples but not in the background field include 2,6-dimethylnaphthalene, benzo[a]pyrene, acetylhexamethyl tetrahydronaphthalene (AHTN), 2,2',4,4'-tetrabromodiphenylether (PBDE 47), d-limonene, and triclosan. For these compounds, biosolids are likely the dominant source to the biosolids-application soils. "

"The first step used to characterizing the effect agricultural watersheds with and without land-applied biosolids had on constituent concentrations in the underlying shallow groundwater was statistical comparison testing to evaluate if there were statistically significant differences ..... Wells OR-687 and OR-688 are located adjacent to and topographically downgradient from the biosolids application fields and were found to be statistically different and have higher nitrate concentrations than all the other wells. "

"To further evaluate any differences in the shallow groundwater quality under agricultural fields with and without land-applied biosolids and the contribution to surface water, the concentrations of EPA-listed contaminants with ceiling concentrations for land-applied biosolids and nutrients were analyzed.... Shallow groundwater samples were collected in December of 2011 and analyzed for contaminants of emerging concern (household-, industrial-, and agricultural-use compounds, sterols, pharmaceuticals, hormones, and antibiotics) from five of the six monitoring wells."

"Concentrations of E. coli and fecal coliform bacteria were higher by orders of magnitude and statistically different in storm samples at the three sites compared to baseflow samples."

"Overall, the most compelling conclusions of the study can be summarized by the following ...

Copper, molybdenum, total Kjeldahl nitrogen, and TP were elevated in the soil from biosolids land-application fields relative to the background field ... Shallow groundwater in transitional zone wells, which are located adjacent to and topographically downgradient from all the biosolids-application fields, were found to be statistically different and had higher nitrate concentrations (medians greater than the EPA drinking-water standard of 10 mg/L) than all the other wells sampled as part of the study."

"Nutrient surface-water concentrations and yields (pounds per square mile), primarily nitrate, were higher at the monitoring site on Collins Creek downstream from the biosolids application fields than the other background study sites"

School of Environmental Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada

Municipal biosolids " can also be non-point source contributors of metals, human-pathogens and
xenobiotics (Singh et al., 2006). The excessive nutrient and metal loads either from improper application rates or unexpected bioconversion is a concern"

"there is always potential for leaching and run-off of microbial contaminants from land-applied
biosolids into surface water and groundwater after extreme weather events including heavy rainfall or flooding (Jamieson et al., 2002; Samarajeewa et al., 2012)."

"MBs (Municipal biosolids) can contain other human pathogens that are not reported or enumerated under the current regulations, including Legionella pneumophila, Staphylococcus aureus, Clostridium difficile and Mycobacterium spp. (Bibby et al., 2010; Viau and Peccia, 2009).

"Treatment processes for MBs can be designed to eliminate many pathogens (Singh et al., 2006); however, unregulated category (CP2, or Class B) products are frequently used as a soil amendment on agriculture lands, in part because wastewater treatment plants often lack the capability to test for the presence of viruses and helminth ova and therefore cannot guarantee their absence."

"Conclusions - Land application of both CP1/Class A and CP2/Class B MBs can lead to drainage and surface water contamination based on an increased concentration of fecal indicators, NO3eN and total-P found in leachate samples."

"This study indicates that some CECs are sufficiently persistent and mobile to be vertically transported into the soil column following biosolids applications to the land surface, even in semiarid regions."

"Triclosan, a synthetic antimicrobial compound, was persistent in biosolids through the 180 days of sampling (Figure 3). Large concentrations in the first (top) soil interval dissipated little over time."

"Concentrations of 4-nonylphenol (sum of all isomers), a detergent or metabolite, were substantial in the Colorado biosolids (approximately 200 ppm) and persisted through at least 180 days post-application...the persistence of this CEC in biosolids and soil indicates the potential for long-term environmental effects."

"A plasticizer and flame retardant, TBEP, was detected in biosolids at relatively small concentrations compared to other CECs but was consistently detected in biosolids through 180 days post-application"

"The results of this study indicate that CECs in biosolids persisted in a real field-application environment. Between 180 and 468 days post-application, select CECs migrated deeper into the soil profile or were taken up by plant roots."

" CONCLUSIONS - This study demonstrates that agronomic applications of biosolids result in detectable concentrations of CECs in soil, and that CECs can persist in surficial biosolids and in soil-biosolid mixtures at detectable concentrations on time scales exceeding one year, particularly under the semiarid conditions present atthis study site."

Toward a Consensus View on the Infectious Risks Associated with Land Application of Sewage Sludge 2011

Emily Viau, Kyle Bibby, Tania Paez-Rubio, and Jordan Peccia

"Other than accidental direct ingestion, the highest public risks of infection from land application are associated with airborne exposure."

"Such analysis demonstrates that the tradition of monitoring pathogen quality by Salmonella spp. and enterovirus content underestimates the infectious risk to the public"

"Over the last ten years, the scientific basis for the Part 503 regulations has been criticized. These criticisms stem fromthe lack of biosolids research on pathogen content and aerosol transport,
the lack of epidemiological studies, and the growing number of anecdotal health complaints from citizens living near land application sites."

"To provide new and important insights into biosolids land application and human health, this review conducted a literature survey on pathogen content and inactivation, compiled and analyzed the results of previous risk studies, and produced new risk estimates using the most up-to-date pathogen content information. Pathogen survey results clearly demonstrate that fecal coliform indicator concentration and associated class A treatment or monitoring requirements do not confirm that class A biosolids are pathogen free, nor is fecal coliform inactivation a conservative measure of pathogen inactivation. The comparison of available quantitative risk studies suggests that, other than accidental ingestions, which the Part 503 regulations to prevent site access are aimed at reducing, aerosols were identified to be the most important route of human exposure to infectious agents. Although there is a consensus among independent risk assessments on the probability of aerosol infection from enteroviruses, inclusion of adenovirus and especially norovirus in risk estimates clearly demonstrates that previous and current risk values for enteroviruses and Salmonella spp. are an underestimate of the total infective risk of pathogens contained in biosolids. Moreover, the consideration of pathogens (such as norovirus) in risk analysis that were not considered during the original analysis for Part 503 rule demonstrates that previous standards based on Salmonella spp. and enterovirus will not achieve the level of protection intended in these regulations."

"The lack of a clearly defined acceptable risk threshold for residents living near biosolids land application sites precludes the use of risk as a definitive measure of safety ... The USEPA originally promulgated biosolids rules based on expedience, reducing pathogen exposure through treatment by the most direct and least-costly approach in view of the uncertainty associated with taking a more risk-based precautionary approach."

"The large diversity of viruses that exist in human populations are potentially excreted into
sewage collection systems and concentrated in sewage sludge. "

"Two important, novel contributions can be drawn from this work’s results. The first is the broad diversity of human viruses revealed in the sludge samples. In every sample surveyed, the degree of viral pathogen diversity is greater than had been previously demonstrated in any environmental or wastewater sample. The realistic implications of this diversity include the need to consider a broader selection of viruses in environmental fate and transport studies, and importance of considering multiple human exposure routes to sewage sludge and wastewater. For the second major contribution, this work demonstrates the utility of metagenomic approaches for viral pathogen identification."

"The results of this study serve to expand our view on the type, occurrence and abundance of viral pathogens in raw sewage sludge and class B biosolids. These results strongly suggest that current regulations for pathogens in sewage sludge that focus on fecal coliform indicators or the presence of Enterovirus, do not capture the full degree of pathogen diversity to which the public may be exposed during biosolids land application. Emerging viruses including Parechovirus, Klassevirus, Bocavirus, and Coronavirus HKU1, were abundantly identified, highlighting previously undemonstrated pathogen diversity in sewage sludge."